Characteristics of epidemic hepatitis A in Baltimore City: implications for control measures

In 1988, a hepatitis A epidemic began in Baltimore, Maryland. A total of 607 cases were reported to the Baltimore City Health Department between the period November 1, 1988, and December 31, 1989. The health department conducted case investigations to identify factors important to the development of control measures. Immunoglobulin was given to appropriate contacts, and an educational campaign was initiated. Of the 607 reported cases, 63% were white and 57% were male. Cases were geographically clustered within 5 of Baltimore's 23 zip codes. Among the 242 adults interviewed, 43% self-reported drug use and 44% were unemployed. Twenty-one percent of the adults and 56% of the children reported contact with either a suspected or confirmed case of hepatitis. Despite control efforts, the epidemic continued through 1990. Barriers to implementing traditional control measures resulted in continuing transmission of hepatitis A in the community.